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1.
Two solutions 5(x, x s) and 6(x, x s) related to the irregular singular point atx=+ of the radial wave equation in Schwarzschild's space-time are studied as functions of the independent variablex and the parameterx s. Analytic continuations of 5 and 6 are derived and their relation to the flat-space case solutions is established. Explicit expressions for 3(x, x s) and 4(x, x s) (the solutions about the regular singular point atx=x s) are given. From these expressions and the analytic continuations of 5 and 6 the coefficients relating linearly 5 and 6 with i (i=1, 2, 3, 4) are calculated.  相似文献   

2.
Let ()() and () () be the von Neumann algebras associated with the space-tiem regions and respectively in the vacuum representation of the free neutral massive scalar field. For suitably chosen spacelike separated regions and it is proved that there exists a normal product state of (), Some consequences for the algebraic structure of the local rings are pointed out.  相似文献   

3.
A globalized version of the following is proved. Let be a factor acting on a Hilbert space ,G a group of unitary operators on inducing automorphisms of ,x a vector separating and cyclic for which is up to a scalar multiple the unique vector invariant under the unitaries inG. Then either is of type III or x is a trace of . The theorem is then applied to study the representations due to invariant factors state of asymptotically abelianC*-algebras, and to show that in quantum field theory certain regions in the Minkowski space give type III factors.  相似文献   

4.
For internal symmetries it is shown that it is possible to construct automorphisms for a Haag-Araki local ring system {(O)} from a local current affiliated to it. Although the chargesQ v for finite volumeV do not converge forV we prove the convergence of the corresponding automorphisms of {(O)}. For external symmetries which map bounded space-time regions into unbounded ones (e.g. translations) we have to require some additional continuity condition on the isomorphisms corresponding toQ v to get convergence.  相似文献   

5.
We prove that an irreducible representation of the Virasoro algebra can be extracted from an irreducible representation space of theSL(2, ) current algebra by putting a constraint on the latter using the Becchi-Rouet-Stora-Tyutin formalism. Thus there is aSL(2, ) symmetry in the Virasoro algebra, but it is gauged and hidden. This construction of the Virasoro algebra is the quantum analogue of the Hamiltonian reduction. We then are naturally lead to consider a constrainedSL(2, ) Wess-Zumino-Witten model. This system is also related to quantum field theory of coadjoint orbit of the Virasoro group. Based on this result, we present a canonical derivation of theSL(2, ) current algebra in Polyakov's theory of two-dimensional gravity; it is a manifestation of theSL(2, ) symmetry in conformal field theory hidden by the quantum Hamiltonian reduction. We also discuss the quantum Hamiltonian reduction of theSL(2, ) current algebra and its relation to theW n -algebra of Zamolodchikov. This makes it possible to define a natural generalization of the geometric action for theW n -algebra despite its non-Lie-algebraic nature.This paper is dedicated to the memory of Vadik G. Knizhnik  相似文献   

6.
The transition matrix elements for coherent and incoherent channels of the neutrinoless e conversion are investigated. The results refer to the 27Al nucleus which has recently been chosen as a target in the MECO experiment at Brookhaven aiming to search for -e conversion events with a sensitivity 10-17. These results are compared to those obtained previously for 48Ti and 208Pb targets. We focus on the contributions to the branching ratio e originating from scalar, vector and axial vector interactions resulting in conventional extentions of the standard model and minimal supersymmetric models with and without -parity violation. With our calculations we extract very severe constraints for the flavor violation parameters.  相似文献   

7.
The 2-point functions of Euclidean conformal invariant quantum field theory are looked at as intertwining kernels of the conformal group. In this analysis a fundamental role is played by a two-element groupW, whose non-identity element =R·I consists of the conformal inversionR multiplied by a space-time reflectionI. The propagators of conformal invariant quantum field theory are determined by the requirement of -covariance. The importance of the -inversion in the theory of Zeta-functions is mentioned.  相似文献   

8.
Starting from a partially ordered set ofC *-algebras i representing algebras of observables of physical subsystems, we derive a topological Hausdorff space as a candidate for some generalized space-time with the help of which one can define a net , of algebras. This opens a way to define a physical theory without an underlying metaphysical manifold, an aspect which may be relevant for the unification of general relativity and quantum field theory.  相似文献   

9.
In paper [1] Fang derived an expression for the complex conductivity of plasma assuming that the distribution function of the electrons is Maxwellian and the collision frequency is directly proportional to their velocity. Since the assumptions are approximately satisfied in the positive column of a d-c glow discharge in Ne, the applicability of Fang's relation is investigated for this case.
[1] , . , .
  相似文献   

10.
Physical principles, design and operation characteristics of a negative mass cyclotron resonance maser inp-type germanium are considered in this paper. The formation of anisotropic inverted distributions of negative effective mass heavy holes in strong electric and magnetic fieldsE H [001], resulting in negative conductivity in the millimetre and submillimetre wavelength ranges, is discussed. The generation is observed at 0.9 to 8mm in low compensated germanium samples with the hole concentration rangeN 0 2×1012 to 2×1014 cm–3 at low temperaturesT 25 K in electric fieldsE 40 to 350Vcm–1. The maser frequency is tuned by the magnetic field corresponding to a cyclotron resonance frequency of carriers with an effective mass ofm c 0.4m 0. The spectral width of the emission in single mode operation does not exceed several megahertz. A pulse duration of 1 to 200 s and a repetition rate off rep 1 to 200 Hz has been obtained limited by sample heating. Possibilities of improving the maser characteristics inp-Ge as well as in other AIII Bv semiconductors and the perspectives of new frequency tuning methods due to the application of uniaxial stress and magnetic field are demonstrated.  相似文献   

11.
It is first shown that a *-automorphism of a factor is inner if and only if it is asymptotically equal to the identity automorphism. Then it is shown that a periodic *-automorphism of a von Neumann algebra is inner if and only if its fixed point algebra is a normal subalgebra of .  相似文献   

12.
LetA be aC*-algebra on the separable Hilbert space , and let be the von Neumann generated byA. LetG be a topological group anda(a) a representation ofG into the group of *-automorphisms ofA. Suppose that each (a) extends to a *-automorphism of , and suppose thata(a)(T)x, y is continuous for eachT inA andx, y and . Then, for a large class of groupsG, one has automatically thata(a)(T)x,y is continuous for allT in andx, y in .Supported in part by NSF Grant GP-9141.  相似文献   

13.
The influence of compression on the edge of self absorption of AgBr single crystals was studied. The measurements were performed at a temperature of –180°C. The shift of the edge of self absorption was studied both in the field of elastic and plastic deformations. The shift of the absorption edge towards the UV end of the spectrum was determined in the field of elastic deformations and towards the i.r. end in the field of plastic deformations. After the ending of the deformation and after unloading the crystal the return of the absorption edge towards the original position was observed.
AgBr
AgBr. –180°C. , . , — . .


The author thanks Prof. Dr. L. Zachoval and K. K. Vacek C. Sc. for their interest in this work and for many comments given during the work.  相似文献   

14.
The usual way of obtaining rate equations (RE) and a single equation for the field amplitude (EFA) from the semiclassical laser equations (Lorenz-Haken model) is reexamined by undertaking a systematic elimination procedure developed in synergetics. The RE and EFA are justified in the case 1 (, ) and case 2 (, ), respectively. We show that, because the eliminated variable happens to contain a considerable contribution from an unstable mode, the usual elimination technique in the case 3 (, ) leads to an inconsistency. As important by-products we obtain the RE and EFA for arbitrary cavity relaxation constant (). Some remarks are given on the direct elimination technique in the non-diagonal representation in the study of instabilities.  相似文献   

15.
A classical, Poincaré invariant dynamical system is developed which contains, besides the natural metric v , an induced metricg v that is generated by a real scalar dynamical field. It is shown that scalar fields whose dynamics are governed by the induced metric can be consistently introduced. Also, point particles which follow timelike quasi-geodesic trajectories can be introduced. The reaction forces acting ong v due to the presence of these fields and particles are computed. A discussion of causality and geometrical confinement is given.  相似文献   

16.
, -, Na, Co, Zn, Ag J 20÷1000 keV. Co, Zn, Te J .
Radiative capture of thermal neutrons on nucleus II
The energies and intensities of gamma rays from the capture of a neutron on Na, Co, Zn, Ag, Te and I nucleus in the 20–1000 keV energy region were measured with a single-crystal, single-channel scintillation spectrometer. New energies of radiative transition were measured when measuring Co, Zn, Te and I nuclei.
  相似文献   

17.
The paper deals with the collective behaviour of electrons which rotate in a magnetic field used in a betatron. It is shown experimentally that there exists strong interaction between the electrons, which leads to the rapid formation of the equilibrium state with characteristic distribution of the charge density in the cross-section of the toroidal beam. The corresponding relaxation time is of the order of 1 sec. A statistical theory of the equilibrium beam is elaborated. Its main result is that the effective radius of the beam is a function of two parameters, one of which is proportional to the thermal energy of the electrons and the other to the perveance of the beam. The charge contained in a toroidal beam of given effective cross-section is equal to the product of the charge the beam would contain at zero temperature and a coefficient, which is a function of the temperature of the beam. Its value is unity at zero temperature and rapidly decreases with increasing temperature. The cause of cooling of the beam is shown.
, . , , . 1S. . , , — I/(E0/q)3/2 (I — , 0 — q ). , , , , , . . .


Now Institute of Vacuum Electronics, Czechosl. Acad. Sci., Prague.

In conclusion the author thanks J. Luká and L. Hyttych for invaluable help in the experiments, A. Rajský for constructing the electronic apparatus and J. Sokol for preparing the miniature probe.  相似文献   

18.
By the methods of luminescence, picosecond spectroscopy, and quantumchemical calculations the mechanisms of electron excitation energy deactivation in some oligothiophenes with intramolecular charge transfer depending on the solvent polarity and viscosity have been investigated. While for 2Npiperidino5(2,2dicyanovinyl)thiophene (PDCVT) the main channel of nonradiative deactivation is the transition to a lower intermediate state with a twisted double bond controlled by the medium viscosity, in the case of (E){2[25piperidino2thienyl]6(trifluoridemethyl)4H4pyranylidene}propanedinitryl (PTFDN) fluorescence quenching is initiated by the solvent polarity. For two other oligothiophenes, 2Npiperidino5cyanothiophene (PCT) and 2Npiperidino5cyanoterthiophene (PCTT), differing in the length of the thiophene chain, we have revealed, along with the effective quenching of fluorescence in shortchain PCT (independent of the solvent polarity and viscosity), an increase in the radiation capacity in PCTT with increasing polarity of the solvent. The possible mechanisms of nonradiative deactivation in the investigated oligothiophenes are discussed.  相似文献   

19.
On the basis of the boundary conditions of the electromagnetic theory an explicit calculation of the absorption in a thin metallic film was carried out with the result that transport and interference components were found to exist. By applying the method to a simple metal-dielectric boundary the physical interpretation was given of the energy balance, which had hitherto been regarded as unclear. It was also explained why the reversibility principle fails when applied to a metal-dielectric boundary.
, . - , . , - .
  相似文献   

20.
The direct interaction of a massless neutral scalar field with an electromagnetic field is investigated with regard for the proper gravitational field. The interaction Lagrangian is chosen in the form Lint=FF, =e–1, where the parameter characterizes the interaction force. Exact static spherically and cylindrically symmetric solutions are obtained. A solution with a finite total field energy is extracted. A comparison is made with the corresponding system in flat space-time. It is concluded that the gravitational field performs a regulatory function.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 25–30, September, 1977.The authors are indebted to Yu. S. Vladimirov for valuable comments.  相似文献   

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